Valve tappet cover hold-down



Dec. 24, 1963 GENOVA 3,115,268

VALVE TAPPET COVER HOLD-DOWN Filed Aug. 10, 1962 INVENTOR ANDREW DEGENOVA by 1Z4 4 FORM E76 United States Patent Gfifice 3,115,268 Patented Dec. 24, 1963 3,115,263 VALVE TAPPET CG'VER HQLD-DGWN Andrew De Geneva, 7117 N. Cicero Ave, Chicago, Ill. Filed Aug. 1%), 1%2, Ser. No. 216,245 9 Claims. (Cl. 229-46) This invention relates to covers for the valve tappets for valve-in-head internal combustion engines and more particularly relates to improved means for holding a valve tappet cover in sealing engagement with the cylinder block of an engine.

A principal object of the invention is to improve upon the hold-downs for valve tappet covers [heretofore in use and to prevent the leakage of oil past the valve appet cover by providing a simple and novel hold-down means for distributing the hold-down force along the rim of the valve tappet cover, to provide a uniform holddown force along the rim of the cover.

A further object of the invention is to provide improved hold-down means for valve tappet covers for internal combustion engines by utilizing a bowed spring in association with each hold-down cap screw, and by yieldably engaging the spring at spaced points along the rim of the valve tappet cover upon tightening of the cap screws to the engine block.

Still another object of the invention is to provide an improved hold-down means for the covers for the valve tappets of valve-in-head internal combustion engines in which a separate hold-down spring extends through each cap screw for holding the cover to the cylinder block and is pressed into engagement with the rim of the cover, and in which a sleeve encircles the screw and limits tightening movement of the hold down spring and serves to exert additional pressure on the rim of the cover intermediate the ends of the hold-down spring.

These and other objects of the invention will appear from time to time as the following specification proceeds and with reference to the accompanying drawing wherein:

FIGURE 1 is a fragmentary view of an internal combustion engine of the valve-in-head type showing a valve tapper cover covering the rocker arms for operating the valves and showing a hold down means constructed in accordance with the principles of the present invention for distributing the hold-down force along the rim of the cover;

FIGURE 2 is a sectional view taken substantially along line II-II of FIGURE 1;

FIGURE 3 is a fragmentary view showing the holddown means in a clamped position;

FIGURE 4 is a top plan View of one form of holddown spring constructed in accordance with the invention;

FIGURE 5 is a plan view of a modified form of holddown spring; and

FIGURE 6 is a side view of the hold-down spring shown in FIGURE 5.

In the embodiment of the invention illustrated in the drawing, 1!) generally designates an engine of the valvein-head type having a conventional valve operating rocker arm assembly projecting upwardly from the head of the engine block. The rocker arm assembly is covered by a valve tappet cover 11 of a conventional form having parallel spaced generally vertical side walls 12, end walls 13 and a top wall 14 connecting said side and end walls together. The cover '11 has a rim 15 extending horizontally outwardly from the side and end walls 12 and 13 having a fiat horizontal bottom 16 engaging a gasket 17 extending about the engine block and resting on the top surface thereof.

The cover 11 has the usual vertical recesses 19 extending vertically along the walls 12 thereof and along which extend machine screws 20 for securing the cover to the engine block.

As shown in FIGURES 1 and 2, the rim has cutwardly extending boss-like portions 21 in registry with the recesses '19, which are apertured as indicated by reference character 22, to accommodate the cap screws to pass through gasket 17 and be (threaded in the engine block.

Referring now in particular to the novel form of holddown means of the invention, associated with each cap screw 20 is a bowed spring 23. As shown in FIGURES 1, 2, 3 and 4 the bowed spring 23 is in the form of a spring wire bent intermediate its ends to form an open eye 24, through which extends a cap screw 20'. Opposite ends of the wire are flattened as indicated by reference character 25 in FIGURE 2, to have firm bearing engagement with the upper surface of the rim 15.

Each cap screw 20 also has a sleeve 27 slidably mounted thereon between the rim 15 and the underside of the bowed spring 23. The sleeve 27 has an internally en larged lower end portion 29 forming a seat for a compnession spring 30 seated at one end on the rim 15 and at its opposite ends on the sleeve 27 within the enlarged internal diameter portion 29 thereof.

A washer 31 encircles the cap screw 20 and abuts the top portion of the open eye 24- of the bowed spring and is abut-ted by a take-up nut 33 threaded on said cap screw.

The bowed spring 233, cap screw 20, washer 3'1 and take-up nut 33 provide a unitary take-up assembly.

When it is desired to clamp the valve tappet cover 11 to the engine block, the sleeve 27 is placed on a cap screw 2t beneath the bowed spring '23 and the spring 30 is seated within said sleeve. The bowed spring 23 is then placed to engage the rim 15 on opposite sides of the recess 19 and the cap screw 20* with sleeve 27 and spring 30 thereon is placed through the apertured portion 22 and gasket 17 and threaded in the engine head. As the cap screw is threaded in the engine head to the desired extent, the take-up nut 33 is tightened along said cap screw to bring the bowed spring 23 into engagement with the sleeve 27 and to compress the spring 30. The bowed spring 23 may be tightened to the extent sufiicient to engage the sleeve 27 with the rim 15 around the apertured portion 22 thereof, although the compression spring 34 may be sufficiently stiff to exert the required pressure on the rim 15 to distribute pressure between opposite ends of the spring 23.

Thus, when the bowed springs 23 are in place and com-pressed as shown in FIGURE 3, pressure will be exerted in the rim 15 around the cap screws 26 and at opposite sides of the bowed springs 23, throughout the length of the cover. This will provide a uniform pressure on the rim 15, to uniformly distribute the hold-down pressure along said rim and to engage the gasket =17 by said rim with sufficient pressure and uniformity to prevent leakage past said rim.

In FIGURES 5 and 6, I have shown a modified form of bowed spring in which the spring is made from a strip of spring steel 35, bowed to the proper contour and having opposite flattened ends 36. The spring steel strip 35 has an enlarged central portion 37, apertured at 39' to accommodate a cap screw 2i) to pass therethrough to bring opposite ends of said spring to resiliently bear on the rim of the valve tappet cover 11, in spaced relation with respect to the cap screw 2%. The fiat metal spring 35 is mounted on the cap screw 29 in a manner similar to which the spring 23 is mounted on its cap screw and is tightened in the same manner the spring 23 is tightened.

It may be seen from the foregoing that I have provided a simple and effective tightening means for the valve tappet cover for the rocker arms of an internal combustion engine, in which the pressure on the rim of the valve ltappet cover on the gasket is uniformly distributed throughout the rim and is continually and resiliently exerted on the rim, and thatsthis provides the uniformity in pressure required to prevent the leakage of oil past the engine block gasket.

While I have herein shown and described several forms in which my invention may be embodied, it may be understood that various variations and modifications in the invention may be attained without departing from the spirit and scope of the novel concepts thereof as defined by the claims appended hereto.

1 claim as my invention:

1. In a valve tappet cover for overhead valve types of internal combustion engines, a generally rectangular cover member having upright Walls, an open bottom and a top wall connecting said upright walls together, and having a rim extending horizontally outwardly of said walls and having spaced apertured portions to r ceive hold-down cap screws, a bowed spring in association with each apertured portion, each bowed spring having a central portion adapted to be received by a hold-down cap screw and having opposite terminal end portions yieldably engaging said rim on opposite sides of the associated hold-down cap screw.

2. In a valve tappet cover for overhead valve types of internal combustion engines, a generally rectangular cover member having upright walls, an open bottom and a top wall connecting said upright walls together, a rim extending horizontally outwardly from the lower end portions of said walls and having spaced apertured portions, a bowed spring in association with each aperturedportion, each bowed spring having a central portion accommodating a hold-down cap screw to pass therethrough and having opposite end portions engageable with said rim at points spaced from said cap screw and tightened to exert yieldable pressure on said rim and engage said rim with the engine block.

3. A valve tappet cover for overhead valve types of internal combustion engines, a generally rectangular cover member having upright walls, a top wall connecting said walls together and an open bottom "having a rim extending horizontally outwardly from said walls for engagement with a cylinder gasket on the engine block, said rim having spaced apertured portions, 9. hold-down cap screw associated with each apertured portion for threading in an engine block, a bowed spring in association with each cap screw at its center and having terminal end portions yieldabl-y engaging said rim, and a sleeve on said cap screw interposed between said rim and said bowed spring and limiting movement of said spring toward said rim and exerting pressure on said rim about said cap screw.

4. A valve tappet cover for overhead valve types of internal combustion engines, a generally rectangular cover member having upright walls, a top wall connecting said walls together and an open bottom having a rim extending horizontally outwardly from said walls for engagement with a cylinder gasket on the engine block, said rim having spaced apertured portions, a hold-down cap screw associated with each apertured portion for threading in an engine block, a bowed spring in association with each cap screw at its center and having terminal end portions yieldably engaging said rim, a spring encircling each cap screw and adapted to abut said rim and exerting pressure on said rim about said cap screw upon tightening movement of said bowed spring to yieldably engage said rim at opposite sides of said cap screw.

5. A valve tappet cover for overhead valve types of internal combustion engines, a generally rectangular cover member having upright walls, a top wall connecting said walls together and an open bottom having a rim extending horizontally outwardly from said walls for engagement with a cylinder gasket on the engine bloclt, said rim having spaced apertured portions, a hold-down cap screw associated with each apertured portion for threading in an engine block, a bowed spring in association with each cap screw at its center and having terminal end portions yieldably engaging said rim, a sleeve on said cap screw interposed between said rim and bowed spring, a compression spring encircling said cap screw and seated on said sleeve and ring and compressed to pressurize said rim about said cap screw upon the tightening of said bowed spring, to bring said sleeve into engagement with said rim and bring the terminal end portions of said bowed spring into engagement with said rim on opposite sides of said cap screw.

. in a valve tappet cover for overhead valve types of internal combustion engines and in combination with a pressurized hold-down therefor, a generally rectangular cover member having upright walls, a top wall connecting said upright walls together and an open bottom having a rim extending horizontally outwardly therefrom, said rim having spaced apertured portions, cap screws adapted to extend through said apertured portions to be threaded in an engine block, a bowed spring in association with each cap screw intermediate its ends and having terminal end portions engaging said rim in spaced relation with respect to said cap screws and a take-up nut threaded on each cap screw for takin up on the associated bowed spring and yieldably engaging the terminal end portions of said bowed spring with said rim.

7. in a valve tappet cover for overhead valve types of internal combustion engines and in combination with a pressurized hold-down therefor, a generally rectangular cover member having upright walls, a top wall connecting said upright walls together and an open bottom having a rim extending horizontally outwardly therefrom, said rim having spaced apertured portions, cap screws adapted to extend through said apertured portions to be threaded in an engine block, a bowed spring in association with each cap screw intermediate its ends and having terminal end portions engaging said rim in spaced relation with respect to said cap screws, a sleeve on each cap screw beneath said bowed spring, a compression spring seated on said sleeve and rim and exerting pressure about said apertured portion, and a take-up nut threaded on said cap screw and operable to compress said bowed spring and yieldably engage the terminal end portions of said spring with said rim, and to compress said spring and exert sealing pressure on said rim about the associated cap screw and at points spaced at opposite sides of said cap screw.

8. A valve tappet cover hold-down in accordance with claim 6 wherein the bowed spring is a wire spring having flattened terminal end portions engageable with said rim and having an open eye intermediate its ends to receive said cap screw.

9. A valve tappet cover take-up in accordance with claim 6 wherein the bowed spring is a flat spring having an intermediate apertured portion and having opposite flattened terminal end portions yieldably engaging said rim, to exert sealing pressure thereon.

References Cited in the file of this patent UNITED STATES PATENTS 

1. IN A VALVE TAPPET COVER FOR OVERHEAD VALVE TYPES OF INTERNAL COMBUSTION ENGINES, A GENERALLY RECTANGULAR COVER MEMBER HAVING UPRIGHT WALLS, AN OPEN BOTTOM AND A TOP WALL CONNECTING SAID UPRIGHT WALLS TOGETHER, AND HAVING A RIM EXTENDING HORIZONTALLY OUTWARDLY OF SAID WALLS AND HAVING SPACED APERTURED PORTIONS TO RECEIVE HOLD-DOWN CAP SCREWS, A BOWED SPRING IN ASSOCIATION WITH EACH APERTURED PORTION, EACH BOWED SPRING HAVING A CENTRAL PORTION ADAPTED TO BE RECEIVED BY A HOLD-DOWN CAP SCREW AND HAVING OPPOSITE TERMINAL END PORTIONS YIELDABLY ENGAGING SAID RIM ON OPPOSITE SIDES OF THE ASSOCIATED HOLD-DOWN CAP SCREW. 